1. Field of the Invention
The invention relates generally to the field of telecommunications, and more particularly to mechanisms for controlling data transmission parameters for wireless communications channels based upon prevailing transmission characteristics of the channels.
2. Related Art
Wireless communication technologies are rapidly advancing, and wireless communication systems are utilized to provide a larger and larger portion of the communications capacity that is currently available to users. This is true despite the additional technological impediments that are faced in implementing a wireless communication system, as compared to a wireline system. For instance, wireless communication systems must deal with issues relating to power control between a base station and its mobile stations in order to maximize the performance of the system, whereas a wireline system does not.
One type of wireless communication system comprises a cellular CDMA (code division multiple access) system which is configured to support voice and data communications. This system may have multiple base stations which communicate via wireless channels with multiple mobile stations. (The base stations are also typically coupled via wireline networks to various other systems, such as a public switched telephone network.) Each base station communicates with a set of mobile stations that are within a sector corresponding to the base station.
It is typically a goal of a wireless communication system to optimize the performance of the system by maximizing the data throughput of the system. This data throughput may include contributions from each of the mobile stations with which the base station communicates. Because the base station typically communicates with multiple mobile stations, the system cannot simply allow communications between the base station and one of the mobile stations to be optimized at the expense of communications with the other mobile stations. On the other hand, the system cannot allow communications with all of the mobile stations to use the highest power levels, data rates and other transmission parameters that are physically possible because they would likely generate so much interference that little, if any, of the data would actually be successfully transmitted. It is therefore necessary for the system to implement controls on the communications with the different mobile stations in order to provide an acceptable level of service to each of them.
A complicating factor in the control of the communications between a base station and various mobile stations is that the mobile stations may be in communication with more than one base station. While a mobile station which is located in close proximity to a first base station generates interference that primarily affects the mobile stations in the same sector, mobile stations that are farther from the base station may generate interference that significantly affects mobile stations in other sectors. While a single base station can handle the first situation relatively easily, it has no knowledge of mobile stations in other sectors, and may therefore require complicated backhaul signaling to handle the second situation. It would therefore be desirable to provide a means to handle the second situation which increases system performance in relation to all of the base stations and corresponding sectors.